Atoms object can have a stray calculator attached between runs

[Andrew-S-Rosen]

Details about the quacc environment

• quacc version: 0.9.2
• Python version: 3.11

What is the issue?

As noted by @zulissimeta, when passing the output["atoms"] object from one @job to another, a calculator can get attached to the original reference due to the mutability of Atoms. This is not desirable because we don't want to store calculator objects in the output schema, and also that was not the calculator used to make that original Atoms object.

How can we easily reproduce the issue?

from quacc.recipes.emt.core import relax_job
from ase.build import bulk

atoms = bulk("Cu")
output = relax_job(atoms)
outupt2 = relax_job(output["atoms"])
assert output["atoms"].calc is None

[Andrew-S-Rosen]

@zulissimeta: Bug is fixed as of #2020.